`{:(,"स्तम्भ 'अ'",,"स्तम्भ 'ब'"),((i),n(n-1) (n-2)...."3, 2, 1",(a),.^(n) C_(r)),((ii),(ul(|n))/(ul(|n-r)),(b),ul(|r)),((iii),.^(n) C_(r) + .^(n) C_(r-1),(c),ul(|n)),((iv),(ul(|n))/(ul(|n-r)ul(|r)),(d),.^(n)P_(r)),((v),.^(n) P_(r)//.^(n) C_(r),(e),.^(n+1) C_(r)):}`

Answer

`(i) rarr (c), (ii) rarr (d), (iii) rarr (e), (iv) rarr (a), (v) rarr (b)`